@vib
I liked pretty much all of it.
The original Macross is pretty rough on the animation side, but it makes up for it with that classic anime vibe, and lack of current anime tropes. And it's got an interesting premise.

Macross Plus is a short OVA. It's decent, but it's only 4 episodes, so don't expect much.

Macross 7 was my favorite, and it's probably the best all around. It's new enough to have good animation, the music is great, and it's still doesn't have any of the current overused anime tropes.

Macross Frontier probably has one of the more interesting story and characters, but I didn't like the music as much, and you start noticing the kawaii/moe anime tropes.

Macross Delta once again has great music, but it's full of moe girls and the childish take on romances that are common now. The story is not as great I'd say.

Each individual series tries to remain watchable as is, without needing their prequels to understand things, but I do recommend watching in order, as there are a few cases of reoccurring characters or references to past events.
Common themes to all of them: giant mech, tree-way romances (most of the time it's 2 girls on 1 guy, Macross Plus and 7 are the exception), and music.

I've put off writing a review on all of them for months, cause there's honestly a lot to go into.